Differential Carrier Bearing Preload Adjustment 8.6 Inch Axle

Special Tools

Note: 

1. Install the drive pinion, if necessary. Refer to Drive Pinion and Ring Gear Replacement.

Note:  Record the measurement for re-assembly.

2. Using an inch pound torque wrench, measure the rotating torque of the drive pinion, it should be 1.7-3.4 N·m (15-30 lb in) for new bearings or 1.1-2.3 N·m (10-20 lb in) for used bearings.
3. If the rotating torque for the drive pinion bearings is not within specifications, adjust as necessary. Refer to Drive Pinion and Ring Gear Replacement.

Note: Before installation of the differential assembly, ensure that the differential side bearing surfaces in the axle housing are clean and free of burrs. If the original differential side bearings are to be reused, the original differential side bearing cups must also be used.

4. Install the differential assembly with the differential side bearings and differential side bearing cups into the axle housing.
5. Insert one 4.318 mm (0.170 in) thick service spacer into the left side of the axle housing.
6. Side the differential assembly towards the service spacer in order to hold the spacer in place.

Note: The J 22779 gage must be installed between the service spacer and the differential side bearing cup.

7. Install the J 22779 gage into the right side of the axle housing.

Note: Over-tightening of the J 22779 gage may spread the housing and result in incorrect shim selection.

8. Tighten the knob on the J 25588 installer until there is moderate drag when the J 22779 gage is moved.
9. Remove the J 22779 gage .
10. Remove the service spacer.

Note:  Record the measurement.

11. Using a micrometer, measure the thickness of the service spacer.

Note:  Record the measurement.

12. Using a micrometer, measure the thickness of the J 22779 gage in 3 locations. Calculate the average of the 3 measurements.
13. Add the thickness of the service spacer, measured in step 11 to the average thickness of the J 22779 gage , measured in step 12. The resulting value is the total service shim thickness without preload for the axle.
14. Insert one BENT 1.016 mm (0.040 in) service shim between the right side differential side bearing cup and the axle housing. The service shim must be installed between the service spacer and the differential side bearing cup.
15. Install the J 22779 gage into the left side of the axle housing. The J 22779 gage must be installed between the service spacer and the differential side bearing cup.
16. While rotating the ring gear back and forth, tighten the knob on the J 22779 gage until there is approximately 0.025-0.051 mm (0.001-0.002 in) of backlash between the ring gear and the drive pinion.
17. Once the correct amount of backlash is obtained, remove the J 22779 gage .
18. Remove the differential assembly with the differential side bearings and the differential side bearing cups.
19. Remove the BENT service shim.
20. Using a micrometer, measure the thickness of the J 22779 gage in 3 locations. Calculate the average of the 3 measurements. This value is the left side service shim thickness without preload.
21. In order to determine the right side service shim thickness, subtract the service shim thickness for the left side of the axle, calculated in step 20, from the total service shim thickness, calculated in step 13. This value is the service shim thickness for the right side of the axle without preload.
22. In order to preload of the differential side bearings and set the backlash to approximately 0.127-0.223 mm (0.005-0.009 in) , take the value determined in step 21 and add 0.203 mm (0.008 in) service shim thickness to this amount.
23. Assemble the left side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of service shims equaling the thickness determined in step 20. Measure the service spacer and the service shims separately. Add the measurements together in order to determine the total shim pack thickness.
24. Assemble the right side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of service shims equaling the thickness determined in step 22. Measure the service spacer and the service shims separately. Add the measurements together in order to determine the total shim pack thickness.
25. Install the differential assembly with the differential side bearings and the differential side bearing cups.
26. Install the left side service spacer and service shim into the axle housing. The service shim must be installed between the service spacer and the differential side bearing cup.
27. Install the right side service spacer between the axle housing and the differential side bearing cup.
28. Install the right side service shim into the axle housing using the J 25588 installer , if necessary. The service shim must be installed between the service spacer and the differential side bearing cup.

Caution: Refer to Fastener Caution in the Preface section.

29. Install the differential bearing caps and the bolts and tighten to 75 N·m (55 lb ft).
30. Rotate the pinion several times to ensure the drive pinion and differential side bearings have seated.

Note: Record the measurement.

31. Using an inch pound torque wrench, measure the rotating torque of the drive pinion and differential side bearings which should be 0.57-1.13 N·m (5-10 lb in) greater than the rotating torque of the drive pinion measured earlier.
32. Calculate the differential side bearing preload by subtracting the drive pinion preload, measured in step 2, from the drive pinion and differential case bearing preload, measured in step 31. Multiply the value obtained by the axle ratio. The differential side bearing preload should be 1.7-4.0 N·m (15-35 lb in).
33. If the differential side bearing preload is not within specifications, add or subtract shim thickness equally from each shim pack as necessary in order to increase/decrease the side bearing preload.
34. Once the differential side bearing preload is correct, measure the backlash and adjust, if necessary. Refer to Backlash Adjustment.
35. Once the differential side bearing preload and backlash is correct, perform a gear tooth contact pattern check in order to ensure proper alignment between the ring and pinion gears. Refer to Gear Tooth Contact Pattern Inspection.

Special Tools

J 25588 Side Bearing Shim Installer

Note: 

1. Install the drive pinion, if necessary. Refer to Drive Pinion and Ring Gear Replacement.

Note: Record the measurement.

2. Using an inch pound torque wrench, measure the rotating torque of the drive pinion which should be 1.7-3.4 N·m (15-30 lb in) for new bearings or 1.1-2.3 N·m (10-20 lb in) for used bearings.
3. If the rotating torque for the drive pinion bearings is not within specifications, adjust as necessary. Refer to Drive Pinion and Ring Gear Replacement.

Note: Before installation of the case assembly, ensure that the side bearing surfaces in the axle housing are clean and free of burrs. If the original bearings are to be reused, the original bearing cups must also be used.

4. Install the differential assembly with the differential side bearings and bearing cups into the axle housing.
5. Insert one BENT 1.016 mm (0.040 in) thick service shim into the right side axle housing. Side the differential assembly towards the bent service shim in order to hold the shim in place.
6. While holding the differential assembly against the bent service shim, install one 4.318 mm (0.170 in) thick service spacer into the left side axle housing.
7. Move the differential assembly to the right until the ring gear contacts the drive pinion. Once the ring gear contacts the drive pinion, continue to move the ring gear towards the drive pinion to until all backlash is removed.
8. While holding the ring gear against the drive pinion, insert progressively larger service shims between the service spacer and the differential side bearing cup until a moderate resistance can be felt.
9. Once the largest service shim has been determined, measure the thickness of the shim using a micrometer. Measure the service shim in 3 locations. Calculate the average of the 3 measurements. Use the average as the thickness for the shim. Record the measurement.
10. Install the service shim that was just measured back into the left side of the axle housing. The service shim must be installed between the service spacer and the differential side bearing cup.
11. Remove the BENT shim from the right side of the axle housing.
12. Insert one 4.318 mm (0.170 in) thick service spacer into the right side axle housing.
13. Move the differential assembly towards the left side of the axle housing. While holding the differential assembly against the left side shim pack, insert progressively larger service shims between the service spacer and the differential side bearing cup until a moderate resistance can be felt.
14. Once the largest service shim has been determined, measure the thickness of the shim using a micrometer. Verify the thickness of the service shim. Measure the service shim in 3 locations. Calculate the average of the 3 measurements. Use the average as the thickness for the shim. Record the measurement.
15. In order to preload the differential side bearing and set the initial backlash to approximately 0.127 mm (0.005 in), adjust the thickness of left and right side shims by doing the following:

15.1.

Subtract 0.152 mm (0.006 in) from the measurement recorded for the left side shim in step 9. Record the measurement.

15.2.

Add 0.356 mm (0.014 in) to the measurement recorded for the right side shim in step 14.

Note: Using a micrometer, verify the thickness of the service shim. Measure the service shim in 3 locations.

16. Select the correct service shim thickness for each side corresponding to the measurements determined above. Calculate the average of the 3 measurements. Use the average as the thickness for the shim.

Note: The service shim must be installed between the service spacer and the differential side bearing cup.

17. Install the left side service shim into the axle housing.
18. Move the differential assembly towards the left side of the axle housing.

Note: The service shim must be installed between the service spacer and the differential side bearing cup

19. Using the J 25588 installer , install the right side service shim into the axle housing..

Caution: Refer to Fastener Caution in the Preface section.

20. Install the differential bearing caps and bolts and tighten to 75 N·m (55 lb ft).
21. Rotate the pinion several times to ensure the bearings have seated.
22. Using an inch-pound torque wrench, measure the rotating torque of drive pinion and differential case side bearings which should be 0.57-1.13 N·m (5-10 lb in) greater than the rotating torque of the drive pinion measured earlier.
23. Calculate the differential side bearing preload by subtracting the drive pinion preload, measured in Step 2, from the drive pinion and the differential case bearing preload, measured in Step 23. Multiply the value obtained by the axle ratio.The differential side bearing preload should be 1.7-4.0 N·m (15-35 lb in).
24. If the differential side bearing preload is not within specifications, add or subtract shim thickness equally from each shim pack as necessary in order to increase/decrease the side bearing preload.
25. Once the differential side bearing preload is within specifications, measure the backlash between the ring gear and the drive pinion and adjust, if necessary. Refer to Backlash Adjustment.
26. Once backlash and differential side bearing preload is within specifications, perform a gear tooth contact pattern check in order to ensure proper alignment between the ring and pinion gears. Refer to Gear Tooth Contact Pattern Inspection.

Differential Carrier Bearing Preload Adjustment 9.5LD Inch Axle

Note: 

1. Ensure that the side bearing surfaces in the axle housing are clean and free of burrs. If the original bearings are to be reused, the original bearing cups must also be used.
2. The drive pinion bearing preload must be within specifications before the differential side bearing preload adjustment can be performed.
3. The differential side bearings must be initially preloaded in order to determine the backlash of the gear set. After the backlash is set, the final bearing preload is set.

Warning: To prevent personal injury and/or component damage, support the differential case when removing the case from the axle housing. If the case is not supported, the differential case could fall and cause personal injury or damage to the differential case.

1. Remove the differential assembly, if necessary.
2. Using an inch-pound torque wrench, measure the rotating torque of the drive pinion bearing. should be 1.7-3.4 N·m (15-30 lb in) for new bearings and 1.1-2.3 N·m (10-20 lb in) for used bearings.
3. If the rotating torque of the drive pinion is less than: 1.7 N·m (15 lb in) for new bearings or 1.1 N·m (10 lb in) for used bearings, tighten the pinion in small increments until the specified rotating torque is obtained.
4. If the rotating torque of the drive pinion is greater than 3.4 N·m (30 lb in) for new bearings or 2.3 N·m (20 lb in) for used bearings, replace the collapsible spacer. Refer to Drive Pinion Bearings Replacement.
5. Install the differential assembly, if necessary.
6. Support the differential assembly in order to prevent the differential assembly from falling out of the axle housing.

Note: DO NOT force the ring gear into contact with the drive pinion.

7. Slide the differential case assembly towards the right side axle housing until the ring gear contacts the drive pinion. This is the ZERO backlash point.
8. If the ZERO backlash cannot be obtained, turn the differential bearing adjuster nut into the axle housing using the J 24429 until the differential ring gear fully contacts the drive pinion to obtain the ZERO backlash.
9. While holding the ring gear against the pinion, turn the differential bearing adjuster nut out from the axle housing using the J 24429 until it contacts the differential side bearing.
10. Using the J 24429 spanner , turn the adjuster nut out from the rear axle housing an additional 2 slots.
11. Install the adjuster nut lock and the adjuster nut lock bolt.
12. Remove the left side differential bearing cap bolts.
13. Remove the left side differential bearing cap.



14. Install the J 22779 into the left side axle housing between the differential bearing bore and the differential bearing cup.

Note: Over-tightening may spread the axle housing and result in incorrect shim selection.

15. Tighten the knob of the J 22779 gauge until there is moderate drag when the J 22779 gauge is moved.
16. Remove the J 22779 gauge and measure it at three different points.
17. Calculate the average of the 3 measurements. The value is the shim thickness required in order to set the initial backlash of the differential assembly.

Note: Verify the thickness of the service shim using a micrometer.

18. Select a service shim of approximately the same thickness to install into the rear axle housing.
19. Install the service shim into the axle housing between the differential bearing bore and the differential bearing cup.

Note: In steps 20, only finger tighten the differential bearing cap bolts.

20. Install the left side differential bearing cap and the bolts.
21. Remove the differential bearing adjuster nut lock bolt and the lock.
22. Using the J 24429 spanner , tighten the differential bearing adjuster nut to ensure that the differential case assembly has a solid contact with the service shim.
23. Rotate the pinion several times in order to seat the bearings.
24. Using the J 24429 spanner , loosen the differential bearing adjuster nut until the nut is free from the differential side bearing.
25. Using the J 24429 spanner , the differential bearing adjuster nut until the differential bearing adjuster nut contacts the bearing.
26. Using the J 24429 spanner , tighten the differential bearing adjuster nut additional 3 slots for new bearings and an additional 2 slots for used bearings
27. Install the right differential bearing adjuster nut lock.

Note: Do not torque the bolt at this time.

28. Install the right differential bearing adjuster nut lock bolt.

Caution: Refer to Fastener Caution in the Preface section.

29. Tighten the differential bearing cap bolts to 85 N·m (63 lb ft).
30. Tighten the differential bearing adjuster nut lock bolt to 26 N·m(19 lb ft).

Note: Rotate the pinion several times to ensure the bearings have seated.

31. Using an inch-pound torque wrench, measure the drive pinion and differential case side bearing preload should be 0.57-1.13 N·m (5-10 lb in) greater than the rotating torque of the drive pinion measured earlier. Record the measurement.
32. Calculate the differential side bearing preload by subtracting the drive pinion preload, measured in Step 2, from the drive pinion and differential case bearing preload, measured in Step 32.
33. Multiply the value obtained by the axle ratio. The differential case side bearing preload should be 1.7-4.0 N·m (15-35 lb in).

Note: Turning the adjuster nut in or out will increase/decrease the side bearing preload.

34. Using the J 24429 spanner to tighten the adjuster nut one slot at a time in or out if the differential case side bearing preload is not within specifications.
35. Once the differential side bearing preload is correct, measure the drive pinion to differential assembly backlash and adjust, if necessary. Refer to Backlash Adjustment.
36. Differential side bearing shims are available in the following sizes:

Shim Sizes

•	5.59 mm (0.220 in)

•	5.64 mm (0.222 in)

•	5.69 mm (0.224 in)

•	5.74 mm (0.226 in)

•	5.79 mm (0.228 in)

•	5.84 mm (0.230 in)

•	5.89 mm (0.232 in)

•	5.94 mm (0.234 in)

•	5.99 mm (0.236 in)

•	6.05 mm (0.238 in)

•	6.10 mm (0.240 in)

•	6.15 mm (0.242 in)

•	6.20 mm (0.244 in)

•	6.25 mm (0.246 in)

•	6.30 mm (0.248 in)

•	6.35 mm (0.250 in)

•	6.40 mm (0.252 in)

•	6.45 mm (0.254 in)

•	6.50 mm (0.256 in)

•	6.55 mm (0.258 in)

Differential Carrier Bearing Preload Adjustment 10.5 Inch Axle

Special Tools

J 24429 Side Bearing Backlash Spanner

Note: 

1. Install the pinion gear bearing retainer or the drive pinion. Refer to Drive Pinion Housing and/or Seal Replacement.
2. Install the differential side bearings, if necessary. Refer to Differential Side Bearings Replacement.
3. Install the differential side bearing adjuster nuts.

Note: Before installation of the differential case assembly, ensure that the side bearing surfaces in the carrier are clean and free of burrs. If the original bearings are to be reused, the original bearing cups must also be used.

Note: If the differential case assembly cannot be installed, turn the differential side bearing adjuster nuts into the axle housing until the differential case assembly can be installed.

4. Install the differential case assembly.

Note: Tighten the bearing cap bolt finger-tight. DO NOT torque the bearing cap bolts at this time.

5. Install the differential bearing caps and bolts.

Note: Do not force the differential ring gear into contact with the drive pinion.

Note: If the zero backlash cannot be obtained, turn the right side differential bearing adjuster nut in towards the rear axle housing until the differential ring gear fully contacts the drive pinion to obtain the zero backlash.

6. To establish the zero backlash point, slide the differential case assembly towards the right side axle housing until the ring gear contact the pinion.
7. Using the J 24429 spanner and holding the holding the differential ring gear against the drive pinion, turn the left differential bearing adjuster nut out from the axle housing until it contacts the differential side bearing.
8. Using the J 24429 spanner , turn the right differential bearing adjuster nut out from the axle housing until it contacts the differential side bearing.
9. Using the J 24429 spanner , back off the left adjusting nut approximately 2 slots in order to obtain the initial backlash adjustment.

Note: Do not torque the adjuster lack bolt at this time.

10. Install the left adjuster nut lock and the adjuster nut lock bolt.
11. Using the J 24429 spanner , firmly tighten the right differential bearing adjuster nut in order to force the differential case assembly into solid contact with the left differential adjuster nut.
12. Rotate the pinion several times in order to seat the bearings.
13. Using the J 24429 spanner , loosen the right differential bearing adjuster nut until the nut is free from the differential side bearing.
14. Using the J 24429 spanner , tighten the right differential bearing adjuster nut until the differential bearing adjuster nut contacts the bearing.
15. Once the right differential bearing adjuster contacts the differential bearing, tighten the differential bearing adjuster nut. using the J 24429 the following additional amounts:
16. Using the J 24429 spanner , tighten the differential bearing adjuster nut an additional 2 slots for used bearings or an additional 3 slots for new bearings.
17. Install the right differential bearing adjuster nut lock.

Note: Do not torque the bolt at this time.

18. Install the right differential bearing adjuster nut lock bolt.

Caution: Refer to Fastener Caution in the Preface section.

19. Tighten the bearing cap bolts to 185 N·m (136 lb ft)..
20. Tighten differential bearing adjuster nut lock bolts to 27 N·m (20 lb ft).
21. Measure the ring gear to pinion backlash and adjust, if necessary. Refer to Backlash Adjustment.